Reasons for the formation of diamonds

Modern science and technology provide new ideas and methods for exploring the formation of diamonds. Diamond is the hardest and simplest gemstone in the world. It is a natural crystal with cubic structure composed of carbon. Its composition is basically the same as our common coal, pencil core and sugar components. Carbon is crystallized at a higher temperature and pressure to form graphite (black), but at high temperature, extremely high pressure and reducing environment (usually it is In an oxygen-starved environment, precious diamonds (white) crystallize. To understand the origin of the diamond, take a look at the original rock containing the diamond.

Since the discovery of diamonds in India, we have been hearing stories of people picking up diamonds on the banks of rivers and riverbanks. This is due to the fact that the original rock containing diamonds somewhere in the upper reaches of the river has been weathered and broken and the diamonds have been carried along with the water. In the downstream areas, the more important diamonds are buried in the sand. What is the original rock of the diamond? In 1870, people dug diamonds in the loess of a farm in South Africa. Since then, diamonds have been digging from the river bed to the loess. Under the loess is hard, dark blue rock. It is the original diamond rock, kimberlite. What is Kimberlite? Kimberlite is an alkalescent ultrabasic volcanic rock formed in the deep part of the earth, containing a large amount of volatile components such as carbonic acid gas. This rock often contains peridotite and eclogite fragments from the deep earth. The main mineral components include olives. Stones, phlogopite, carbonates, pyroxenes, garnets, etc. Studies have shown that Kimberley magma is formed 150 kilometers deep below the Earth. Since this rock was first discovered in Kimberley, South Africa, it was named after the place name.

Another kind of diamond-bearing rock is called lamproite. It is an overbased magnesia volcanic rock. It is mainly formed from leucite and volcanic glass. It can contain minerals such as pyroxene and olivine. Origin is in Argyle, Western Australia.

Scientists have found that diamonds and their intermediate inclusion minerals from different mines around the world have been found to have a formation pressure of 4.5-6.0 Gpa (equivalent to a depth of 150-200 km) and a temperature of 1100-1500 degrees Celsius. Although in theory, diamonds can be formed in all phases/stages of the earth's history, most of the diamonds currently mined are formed mainly during the two-year period of 3.3 billion years and 12-17 billion years. For example, some South African diamonds are about 4.5 billion years old, indicating that these diamonds have begun to crystallize deep in the earth shortly after the birth of the earth. Diamonds are the world's oldest gemstones. The formation of diamonds requires a long historical process, which can be confirmed by the fact that diamonds are mainly produced in the ancient stable continental regions of the world. In addition, the impact of Earth's extraterrestrials on the Earth generates instantaneous high temperatures and high pressures, which can also form diamonds. For example, the Soviet Academy of Sciences reported that diamonds were found in meteorites prior to 1988, but diamonds formed by this effect have no economic value.

The scarce diamonds are mainly found in two types of rocks, one being peridotite and one being eclogite, but the former only has economic significance. Diamond-bearing peridotite has so far been found in two types: Kimberlite (name derived from the name of South Africa - Kimberley) and lamproite. Both of these rocks are caused by volcanic eruptions. The resulting rocks, formed in the depths of the earth, are carried by volcanic activity to the surface or shallow parts of the earth. These magma are mostly produced in rock and tubular shapes and are therefore commonly referred to as "tube ore" (ie, primary ore). Diamond-bearing kimberlite or potassium-magnesium lamprophyre is exposed on the surface of the earth and weathered and broken by wind and rain and other extraterrestrial forces. Under the currents of washed water, the broken rock and the drill are brought to the riverbed and even the coast. The area is multiplied to form an alluvial sand deposit (or secondary deposit).